It is often desirable to inject steam simultaneously into more than one well zone of an oil bearing formation for increasing the recovery of the oil. Various methods for performing this operation are described in the Society of Petroleum Engineers Paper No. 15472, entitled "New Methods for Controlled Injection of Steam Into Multiple Sands" dated Oct. 5, 1986. However, this paper points out that it is desirable to maintain the quality of steam injected into each different well zones. That is, if the steam quality is insufficient, by containing too much water, an unsatisfactory steam quality and flow rate division occur between the different zones. In one example given of a two zone steam injection, the top zone received quality steam, ranging from 60% to 80%, while the bottom zone received only 30% to 40% quality steam. That is, the bottom zone received most of the water in the steam.
The present invention is directed to a method of and apparatus for injecting steam containing water into multiple well zones to obtain a more uniform division of water to each zone. This is done by collecting the water in the steam and more evenly dividing the water between each of the well zones to provide a more uniform quality of steam injected into all of the zones even if the division of steam between the zones is not equal.